在解数学竞赛题时,如果仅用课本上的一些常用的方法,有时就显得不够用了.如果将题中的一些对象看做是互相关联的,依次地可以排队,逐个地进行推算,有时很奏效,这就是人们常说的递推法.在这里,我们利用它来解一些有关的竞赛题.现例说如下. When solving mathematics contests, if you use only some of the commonly used methods in textbooks, it may not be enough. If you look at some of the objects in the question as interrelated, you can queue up one by one to calculate them. Sometimes, It works, and this is what people often call recursion. Here, we use it to solve some of the contest problems. The current example is as follows.